Ophthalmic surgical procedures often involve extracting tissue and fluid from the patient's eye. For example, phacoemulsification involves using ultrasonic energy to break the lens of the eye into small pieces that are promptly aspirated from the lens capsule. Extraction of fluid and other substances from an eye will cause depressurization of that eye, which can cause a number of problems. To counteract these problems, a replacement fluid is simultaneously injected into the eye to keep the pressure within the eye at an acceptable level. In a further example, vitreoretinal surgeries involve the cutting and extracting vitreous fibrils from the eye. During such a procedure, a replacement fluid is also simultaneously supplied to maintain the intraocular pressure at an acceptable level. It is desirable to provide such fluid infusion in a versatile and efficient manner.